Dress for formal wedding abroad

[someon]

I going to a wedding in Portugal in August
It says formal wear on the invite I'm struggling to find something to wear !
Its going to be very hot so I'd rather like the idea of a dress with straps no sleeves or open to a nice jumpsuit I'm 5ft 2 in my 40s with a big bust 34GG / 36G I'm a size 16 on top and 14 bottom half this is the problem it's getting the right fit for me this I'm struggling with
Anyone any ideas I'm getting desperate I like floral / ditsy dress I don't want to wear a dark colour either or anything too frumpy as I like trendy clothes. Help.

What's the max budget?

Could stretch to £100

Is it a Portuguese wedding?

Is it in a church, in which case you may need to cover shoulders, check. I'd go with a cross over front style, plain materials look more formal, and stiffer rather than floaty again adds formality. Trawling charity shops might bag you a great dress at a decent price

It's not in a church it's a outside wedding and not Portuguese the couple are both from the uk

I got 3 dresses today that I ordered online they are going back as were awful nothing seems to fit right around my boob area they make every dress I wear look frumpy
I also wear good bras they cost me a fortune too so it's not the bras it's just how big more wide then in your face
It's so depressing ! I just want to wear a dress I look nice in and feel comfortable in !

What about something like this OP

Search Vinted.

I like Lady Vintage dresses. How about this? https://ladyvlondon.com/products/lyra-dress-koi-floral?variant=45379821764916